VMware had release ESXi 6.0 Update 1 and vCenter 6.0 Update 1 a couple weeks ago. To follow that up, Dell has no released their customized ISO for ESXi 6.0 Update 1 which includes their drivers, etc. You can find the ISO at the following link. Please post up if you have any issues with this release! I’ll be upgrading my Dell R710 in a few moments.
Edit: Booted the ISO over iDRAC and chose to upgrade – no surprises, everything went as predicted: